[interchange] Fix bug introduced in commit 7401515

[Josh Lavin]

commit 25fb72265a7fb53877add4767827d69d5532beb7
Author: Josh Lavin <digory at cpan.org>
Date:   Tue Jan 17 14:16:57 2017 -0800

    Fix bug introduced in commit 7401515
    
    - this caused Values space to inherit things that should have been
      placed in Scratch

 lib/Vend/UserDB.pm |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/lib/Vend/UserDB.pm b/lib/Vend/UserDB.pm
index 50e1529..0aa9af8 100644
--- a/lib/Vend/UserDB.pm
+++ b/lib/Vend/UserDB.pm
@@ -986,7 +986,7 @@ sub get_values {
 	my($self, $valref, $scratchref) = @_;
 
 	my $same;
-	if($valref eq $scratchref) {
+	if($valref and $valref eq $scratchref) {
 		$same = 1;
 	}